// @ts-nocheck
// 判断传入的字符串字面量类型中是否含有某个字符串

type Include<T extends string, C extends string> = 
T extends '' ? 
(C extends ''? 
true : false ): // 这里是排空的情况 
(T extends `${infer L}${C}${infer R}`? true : false) 

type a1 = Include<"Jiang", "J">; // true
type a2 = Include<"", "J">; // true
type a3 = Include<"", "">; // true
type a4 = Include<"hahaha", "">; // true


export {}